Summary The IBA is the location for one of only two records since 1990 of the Critically Endangered Night Parrot. When inundated, it supports up to 270,000 waterbirds, including more than 1% of the global population of 14 species (six waterfowl, three cormorants, and single species of grebe, heron, ibis, stilt and tern). It also supports three near-threatened and five arid-biome-restricted species.

Site description The IBA is an extensive (100 km long by 10 km wide) ephemeral saltmarsh between the Chichester and Hamersley Ranges in the Pilbara. The boundary of the IBA is intended to capture the contiguous floodplain of the central Fortescue River basin subject to episodic or seasonal flooding. The eastern basin has a clearly-defined area of maximum flooding, which is all taken in the IBA. West of the Goodiadarrie Hills, the basin narrows and the IBA is extended to the road north from Wittenoom to include a series of swampy areas, which are patchy but mapped as a contiguous area, and are important for nesting waterbirds. Surface inflow is from the upper reaches of the Fortescue River, originating about 130 km south-west of Roy Hill, and other creeks emerging from the ranges. Extensive inundation is episodic, once every ten or more years. Mean annual rainfall at nearby Wittenoom is 403 mm and it is 263 mm at Roy Hill. The site is bisected by the Newman-Port Hedland railway line and road. The IBA should be extended to include the adjacent spinifex-dominated foothills where Night Parrots have been recorded, but their habitat requirements are not known well enough to determine an IBA boundary.

Key Biodiversity When inundated, the IBA supports large numbers of waterbirds, with total counts of 268,758 in August 1999, 94,920 in May 2000, 252,943 in August 2000 and 275,638 in September 2003. Substantial but sub-threshold numbers of Freckled Duck (up to 137), Australian Pelican (up to 4552) and Eurasian Coot (up to 81,583) have been recorded (Halse et al. unpublished data). At least seven Star Finch were present at Minga Well in 2005 (R. Davis in litt. 2008).